Here's Why Changing Your Engine Oil After 5,000 Miles Will Destroy Your Car

About this video

• Video Title: Here's Why Changing Your Engine Oil After 5,000 Miles Will Destroy Your Car
• Channel: Scotty Kilmer
• Speakers: Scotty Kilmer
• Duration: 21:24

Overview

This video explains how fuel dilution in engine oil, particularly in modern Gasoline Direct Injection (GDI) engines, can lead to premature engine wear and damage. Scotty Kilmer advises on the importance of frequent oil changes (every 5,000 miles) and using full synthetic oil and filters to combat this issue, while also touching on transmission fluid maintenance.

Key takeaways

• GDI Engines and Oil Dilution: Gasoline Direct Injection (GDI) engines operate under much higher fuel pressures (up to 2,000 PSI) compared to older port injection systems (35-45 PSI). This high pressure can force raw gasoline past piston rings into the engine oil, diluting it and reducing its lubricating properties.
• Consequences of Diluted Oil: Diluted oil has lower viscosity and cannot effectively lubricate engine components like camshafts and pistons, leading to increased wear. It can also contribute to sludge and deposit formation, especially on intake valves in GDI systems where fuel is injected directly into the cylinder, bypassing the valves.
• Differences from Diesel Engines: Unlike gasoline, diesel fuel is a lubricant and doesn't cause the same destructive dilution. Diesel engines can tolerate longer oil change intervals because their fuel doesn't degrade oil's lubrication properties in the same way.
• Importance of Frequent Oil Changes: To combat oil dilution, especially in GDI engines, it's crucial to change the engine oil and filter frequently, recommending at least every 5,000 miles with full synthetic oil and filters.
• Transmission Fluid Maintenance: The video also stresses the importance of regular automatic transmission fluid changes (every 30,000-40,000 miles), debunking the myth of "lifetime fluid," as neglected transmission fluid can lead to costly repairs.